Step 9: Use your battery – Going soft

Step 10: Final notes

Please remember, most of these tips only lower your power usage a small bit. It's when they are combined that you can sometimes work minutes (to be pe...

People just seem to keep forgetting the easiest things about notebooks.
Especially the battery is a continuing point of frustration. How many times hasn't it happened that when you pull out your notebook, the battery is dead, even if you've just recharged it a few hours before.

Well, it's time to take care of that!

Next are a few tips and tricks to both extend the life of your battery and to make sure that you can work as long as possible on a single charge, so that you can save energy and make sure it takes just a bit longer until you have to throw your battery away, which is good for the environment.

Step 1: First things first...

In order to take care of the battery, it might be useful to know a few things about them. Notebook batteries can be made of 3 types of chemical compositions.

The first ever notebook batteries were Nickel Cadmium (NiCd). In that time, they had a high energy output and they could be charged quite quickly, which is very convenient in a notebook. The NiCd, however, isn't used as much in electronic devices because the later types have yet a higher energy output.

The second type of batteries, were the Nickel Metal Hydride (NiMH) batteries. These batteries are still widely used and particularly known for a drawback, namely the memory effect. These batteries needed to be completely discharged in order to keep its capacity at a maximum.

UPDATE: thanks to Flea i syarted to research a bit more on the memory effect and apparently the memory eefect occurs mainly in the NiCd batteries, as Flea said. NiMH still suffer from this phenomenon though in fewer cases.

The newest type of batteries and the ones that are dominating the market by now, are the Lithium Ion (LiON) ones. These batteries have solved the memory effect found in the NiMH batteries. Instead their capacity is to be held at a maximum by only partially(!) discharging it. The only problem is that the calibration may turn out a bit off. How to solve this is mentioned later in this instructable.

I don't know that much about Lithium Ion batteries. I'm a wizard with NiCds and NiMH. I had a customer that manufactured aeronautical grade NiCds and NiMH's. Generally, these looked like big see-through lead acid batteries. "Aeronautical grade" translates into our lingo as "BETTER than *perfect*". They power critical airplane stuff, where dead batteries equal dead people. By FAA law, they're changed out at three year intervals. They've let me "borrow" some of these. After 15 years, they still work great. I hold a BSEE AND I ask far too many annoying questions, except that I'm 6'2", a solid 235#, and folks are afraid to tell me to shut up. They explained everything in great detail, and even loaned me several very thick books containing far too much precision math for my "shop math" tastes. NiCd's use sintered metal. This greatly increases their surface area, and available current. If you always discharge them, let's say, 10% and charge, a barrier builds up @ 10%, ergo memory. Never totally discharge any rechargeable. The weakest cells will reverse charge, and you'll need a PhD in batteries AND a minor miracle to recover them. NiCds and NiMH are 1.2 volts per cell fully charged all the way to fully discharged, then they take an immediate and sudden dive. AS SOON AS YOU NOTICE *A*N*Y* DECREASE IN VOLTAGE, put them on the charger. I know guys who use their NiCds/NiMH's many hours every day, and have been using the same batteries for ten years or more. They periodically use a conditioner on EACH CELL. This is a smart charger/smart discharger. First, it takes a cell to full discharge (just under 1.2 volts). Then it brings the cell up to fully charged. A pulse charger will charge your batteries only to 90% capacity, but it will NEVER heat the batteries, making them last longer than Methuselah. I kluged one by using a transformer with an output voltage 3 to 4 times what I needed, using a SINGLE rectifier for half wave, and several zener diodes in series to drop the voltage to spec, in the process passing only the very tip of the wave, which is effectively a pulse. I used this to float charge NiCds for an emergency backup communications switched packet system. Normally, float charging NiCds will kill them in a year or two. When I took this system off the air after about ten years, the NiCds were nearly as good as new.

If you experience a shortened battery life and the retailer or manufacturer blames you for not removing it when you were on AC, complain loud and long. Manufacturers can easily (and cheaply) build a circuit into the charging circuit to bypass it when the battery is fully charged (and not 'reconnect' it until it is significantly discharge, e.g. 95%), thereby eliminating the need to remove the battery. Removing the battery is counter-intuitive and needless. It could also lead to damage.

Particularly in the case of Lithium batteries this is a highly valid comment. The battery container is fitted with electronics to ensure that charge is evenly distributed among the cells, and that insane number of contacts between the battery and the computer is to prevent a single cell from over charging. It is not the constant charging that causes the battery to get hot--it's the inadequate ventilation of the CPU.

Lithium batteries begin decaying the moment they leave the production line--and people wonder why there's a 12V gel-cell hooked up to the back of my video-camera...

While I agree with this idea in principle, I think it is doesn't specify beneficial and non-beneficial scenarios. For example, if the DVD was an reference suite that needed to constant access, or a database, or music, video, or a movie, I would tend to agree that making an image was a better solution. But only if the image was made prior to running on battery. Creating the image may consume more power than casual access.

The other thing to consider is that most systems have a 'slow spin down' (or similar) feature for CD/DVD drives that keeps the drive spinning slowly using small power pulses and inertia until the next read. For casual access this might be all that's needed.

My recommendation is that people try it out and tweak it to suit their situation. Maybe they could post the results here so others can benefit form their experience. The next chance I get, I'm going to watch a DVD image and actual DVD and see what the difference is in terms of battery use.

Overall, a good instructable. I have issues with a few things though.The memory effect is a voltage depression effect. It is mostly noticable in NiCads, not NiMH. It can be repaired. Source1Source 2The reason manufactures switched from NiCAD to NiMH, then to Li-ion is not because of the memory effect, but because of energy density. Lithium based batteries have much higher energy densities allowing devices to run longer. Pretty much all laptop manufacturers use Li-ion batteries now.SourceYou should change your title to "Extend Laptop Life". Less vague.Another way to extend life is to undervolt the laptop. This allows the cpu to draw less power and run cooler (which uses the fan less to save power). For Intel CPU's you can use NHC. For AMD CPU's you can use Puma state control.

All very good advice. It's only recently that laptops have started turning off the charging current when the battery is fully charged. Previously the LiON batteries would sit there having current pumped into them even when fully charged, causing them to heat up. The thing that these batteries REALLY hate is overheating. It sells more batteries I suppose (which, of course, aren't covered by the warranty).

a couple more things 1) li-ion really don't like being discharged to less than 10%, so keep them above 15% charge if possible. 2) if not using a battery for a while, get it to 50% charge, and refrigerate (not freeze!) it. this will prolong its life

I would really appreciate it if you would rate and vote for the contest(s) this instructable might be in. Many thanks in advance. Also, if you see things that could be done better, please inform me and i will see into it.